Incandescent electric lamp.



J. H. BIRCH.

INCANDESCENT ELECTRIC LAMP.

APPLICATION FILED AUG.8.1913.

1,150,173, Patented Aug. 17, 1915.

JOHN HIEAPS E1303, 01' GATLIFF, KENTUCIY.

' INCA1TDESCENT ELECTRIC LAME.

Speclflcation cf Letters Patent.

Application flled August 8, 1913. Serial No. 733,750.

To all w7z,om it may concern V Be it known that I, JOHN HEAIS Bmc, a citizen of the United States, residing at Gatlifi, in the count; of Whitley and State of Kentucky, have invented new and useful Improvements in Incandescent Elect nc Lamps, of which the following is a spec1fication.

This invention relates to improvements in illuminating devices, and it has for its primary objects to provide an incandescent electric lamp of improved construction embodying a plurality of filaments which are connected in parallel to the terminals and are preferably circular and arranged concentrically one within another, and to provide an improved bulb to inclose the filaments, said bulb forming a reflector at the rear and a lens at the front thereof, the bulb being also shaped so that it will fit readily into 'lamps as commonly used on locomotives, automobiles, street cars or other vehicles, and a plug may be located at different positions on the bulb whereby the bulb can be supported by a lamp socket whether the same be arranged horizontally or vertically and electric current thereby supplied to the filaments.

A lamp of this character will have a relatively high candle power and hence may be used advantageously as a substitute for arc lamps as heretofore used for headdights, and the construction of the filaments is such that they will continue to give light even though one or more of the filaments or portions thereof may become broken or burned out.

To these and other ends, the invention consists in certain improvements, and combinations and arrangements of parts, all as Will be hereinafter more fully described, the novel features being pointed out particularly in the claims at the end of the specification.

In the accompanying drawing:Figure 1 is a front elevation showing one embodiment of a lamp constructed in accordance with the present invention; Fig. 2 represents a central vertical section of the lamp as shown in Fig. 1; Fig. 3 isa view similar to Fig. 2 showing the terminal and supporting plug arranged in a diflerent position.

Similar parts are designated by the same reference characters in.the several views..

Illuminating devices embodying the present invention are capable of use for illuminating purposes in general, but they are particularly adapted for use in those cases where a high powerlig ht is required such, for example, as on head-lights of locomotives, automobiles, street cars and other vehicles. The device embodies a bulb 1 composed referably of an integral glass structure, t e front being shaped to form a lens or bulls-eye 2 and the rear is concave and may be silvered or otherwise ti*eated to form a refiector 3. The present invention provides an electric lamp of improved construction which is positioned behind the lens 2 and in proper relation to the focus of the reflector 3. In its preferred construction, a plurality of incandescent electric filaments 4 are used which are circular in form and of difierent diameters, these circular filaments being arranged concentrically and one positioned within another. These filaments are so connected to the lamp terminals that they will receive the electric current in parallel. In the construction shown, the filaments are connected at diametrically opposite points to a pair of terminal wires 5 and 6, these terminal Wires being rigidly supported within the bulb by the lamp base 7 and they are electrically connected to the threaded sleeve 8 and center contact 9 respectively. That portion of the lamp base which projects to the exterior of the bulb is adapted to fit into a correspondingly formed socket arranged in the casing which is to contain the lamp or illuminating device. Obviously, bases and sockets of diflerent kinds can be used. It will also be understood that the base of the lamp bulb can be located at difierent positions on the bulb to meet the requirements and diflerent conditions. For example, While in Figs. 1 and 2, the base is shown at the bottom of the bulb, this base. can be arranged at the rear of the lamp and in center of the refiector, the latter construction adapting the lamp to sockets which are arranged horizontally. An incandescent electric lamp embodying a plurality of filament.s which are connected in parallel to the terminals not only concentrates a high candle power within a small space, but will continue to give light even though one or more of the filaments may become broken or burned out. Also, should one half of any one of the filaments become broken or burned out, .the remaining half of this filament Will continue to burn. The bulb which incloses the filaments is preferably of heavy lass and sealed after having the air withrawn therefrom as is the case with ordinary incandescent electric lamps.

I claim as my invention 1. An incandescent electric lamp comprising a bulb compsed of glass, the rear portion of which forms a concave reflector, a plurality of concentric filaments of graduated sizes, and terminals connected in parallel to said filaments and supporting them in coperative relation with the reflector.

' 2. An incandescent electric lamp comprisin a bulb, the rear portion of wh1ch is provied with a concave refiector, a plurality of filaments of graduated sizes arranged concentricafly of one another and with respect to said refiector, and terminals connected in parallel to said filaments and supporting them in coperative relation with the reflector.

3. An incandescent electric lamp comprising a bulb having a concave reflector at the rear thereof, and a plurality cf circular filaments arranged concentrically with'one another and said refiector, the inner filament of smallest diameter being located closer to the 'reflector than the outer filament of largest diameter.

4. An incandescent electric lamp comprising a bulb having a concave r;efiector at the rear thereof, a set ofendless circular filaments arranged concentrically with one another and said reflector and occupying different planes in front of the reflector, and terminals connected to said filaments at diametrically opposite points and supporting the filaments.

5. An incandescent electric lamp comprising a bulb having a concave reflector at the rear and a lens at the front thereof, a set of endless circular filaments arranged concentrically With one another and said reflector and lens, and terminale connected to said filaments at diametrically opposite points and supporting the filaments.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

JOHN HEAPS BIRGH.

Wit1iesses:

GARFIELD HOWARD, B. M. ARCHER. 

